Results of plating seems more accurate than before as the starting number of cells in M9 and LB medium should be theoretically similar assuming the centrifuging was done properly. If the starting number of cells are the same, the LB agar plates (at a certain dilution) should contain similar number of colonies for both M9 and LB media. However, the number of colonies vary by a lot (compare at 10^-10 and 10^-12: Both LB and M9 (centrifuged) produced similar number of colonies upon plating).